THURSDAY, July 23, 2015 (HealthDay News) -- Eating a healthier diet might reduce the risk of problems with certain brain functions as you age, findings from a recent study suggest.

Older adults with healthier diets reduced their odds of impaired "executive function" by 35 percent. Executive function refers to a collection of things done by the brain, including memory, reasoning, multi-tasking, problem-solving and planning skills.

"Healthy diet might affect cognition [thinking skills] through several mechanisms," said study co-author Carol Derby, associate professor of neurology and of epidemiology and population health at the Albert Einstein College of Medicine in New York City.

"Healthy diet is associated with reduced rates of cardiovascular disease, with more healthy weight and with reduced risk of diabetes, all of which are risk factors for cognitive decline and dementia," she explained.

However, this study wasn't designed to show that eating more healthfully actually caused the better brain function, or that a good diet could prevent Alzheimer's or dementia. The study was only designed to find an association between a healthy diet and better brain function.

Researchers presented the findings this week at the Alzheimer's Association International Conference in Washington, D.C. Findings presented at meetings are generally considered preliminary until they've been published in a peer-reviewed journal.

For the study, researchers asked nearly 550 seniors about their diets. Their average age was 80 years old. None of them showed signs of dementia.

The study volunteers were asked to recall how many servings they eat weekly of grains, fried foods, snacks, sweets, soft drinks, fats, alcohol, fruits and vegetables, and specific dairy and meat products.

Each participant also took several tests to determine memory and thinking skills, along with executive function. Participants were considered to have impaired function if they scored substantially lower than average on a particular collection of skills.

After taking into consideration participants' age, education, sex, race and heart conditions, the researchers determined that those with a healthier diet had 35 percent lower odds of impaired executive function. No links between diet and overall memory or thinking were found, the researchers said.

When the investigators looked at differences between black and white participants, they found no link between diet and any brain health test in blacks. The lack of a difference may be because black individuals tend to have a greater risk of vascular conditions, the researchers said.

"We know that a diet that is too caloric or too loaded with sugars can lead to insulin resistance and vascular disease that, in turn, are not good for the brain," said Dr. Marie Csete, president and chief scientist of Huntington Medical Research Institutes in Pasadena, Calif.

"We know that mood is affected by the content of food, and that mood affects sleep patterns, and sleep is an important factor in maintaining brain health," added Csete, who was not involved with the study.

Still, there are other explanations for the findings than a healthier diet causing better brain health, Csete suggested, such as overall healthier lifestyles among those who also eat healthier diets.

"You might think that people who are interested in preparing healthy foods for themselves would also be interested in having more physical activity, in not smoking and in controlling their cholesterol levels," Csete said. "Exercise is a very positive modifiable factor to help stave off loss of cognitive function."

It's also not clear what specifically makes up a healthy diet, though there are some general guidelines that make sense, said Dr. Luca Giliberto, an investigator physician at the Litwin-Zucker Research Center for the Study of Alzheimer's Disease at the Feinstein Institute for Medical Research in Manhasset, N.Y.

"One would assume that a diet rich in natural vitamins, low in saturated fats and rich in omega-3 fats, low in refined sugars and rich in high-quality proteins would do the trick," Giliberto said. "In reality, it is probably the balance of all these aspects and the attached quality of life, physical and mental activity, and personal satisfaction that complete the recipe for good cognition."

Meanwhile, an excess of refined sugars, saturated fats and too few natural vitamins and good proteins increases the risk of atherosclerosis and oxidative stress in the body, which can contribute to mental decline, Giliberto explained.

"It is never too late to start prevention, especially when it comes to food and physical activity," Giliberto said. "The two often go hand in hand."

More information

For more on keeping your brain healthy, visit the Alzheimer's Association.

SOURCES: Carol Derby, Ph.D., associate professor of neurology and of epidemiology and population health, Louis and Gertrude Feil Faculty Scholar in Neurology, the Albert Einstein College of Medicine, New York City; Marie Csete, M.D., Ph.D., president and chief scientist, Huntington Medical Research Institutes, Pasadena, California; Luca Giliberto, M.D., Ph.D., investigator physician, The Litwin-Zucker Research Center for the Study of Alzheimer's Disease, the Feinstein Institute for Medical Research, Manhasset, N.Y.; July 21, 2015, presentation, Alzheimer's Association International Conference, Washington D.C.